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Thermoworx Blackmorph



Jolly useful stuff for hacking and fixing

Do you like fixing stuff? You may have come across Sugru, which is a self-hardening silicone rubber, kind of a mouldable glue. Thermoworx Blackmorph is a different kind of material – a thermoplastic polymer – but it can be put to use in many of the same ways, and some different ones, and it scores over Sugru in that it's cheaper, remouldable and reusable.

  • Pros: Great for fixing and hacking stuff, remouldable, reusable
  • Cons: Very hard when set so not ideal for some bike-related tasks, not a glue so surface prep is important

Blackmorph (Whitemorph is also available, as are colour pigments to make your own colours) melts at 62°C, so getting it ready to use is just a case of popping some granules in a cup and pouring on some boiling water. Once it's melted you can form it into any shape you want.


It sets to a plastic hard enough to be structural. That means it's not ideal for ergonomic tasks like fitting your handlebars to your hand shape, as it's not particularly comfy to hold. But you can do all sorts of other stuff with it.

I've mended some cycling shoes with it, added some wings to a tricky bolt to make it easier to undo, fixed a windscreen wiper (okay, not a specifically cycling-related task), replaced the nose bits on some sunglasses... that sort of thing. Basically, hacked stuff.


If you get it wrong then you can just heat the Blackmorph up again with a hair dryer and re-mould it or pull it off and re-use it. Those are the two main plus points over Sugru. That's a one-time affair – it sets and that's that – so you have to use a whole packet if you open it, and if you're not happy with the results you need to start again.

> Bikepacking basics: bike repair and first-aid kit

Blackmorph isn't a glue, so it's important to prepare surfaces well: make sure they're clean, and scuff them up a bit with some emery board to help adhesion. I found it also helps to heat up whatever you're fixing with a hairdryer where you can, especially if you're tackling a big job like a shoe repair.

Anyway, it's just really useful stuff to have knocking about for all those minor hacks and repairs. I can thoroughly recommend it.


Jolly useful stuff for hacking and fixing

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Make and model: Thermoworx Blackmorph

Size tested: Black

Tell us what the product is for and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?

Thermoworx says, "Blackmorph® is a reusable thermoplastic polymer with a low melting point. The pellets fuse together, soften and turn semi-transparent when heated to over 62°C allowing users to easily shape the polymer by hand! Blackmorph® hardens to a solid, black, non-brittle, strong material that truly has unlimited possibilities. Blackmorph® has no shelf-life and is fully biodegradable. Not compatible with Thermoworx colouring pigments."

Tell us some more about the technical aspects of the product?

Thermoworx lists:

Heat in hot water over 62°C

Mould by hand




Black edition

Rate the product for quality of construction:
Rate the product for performance:
Rate the product for durability:
Rate the product for value:

Tell us how the product performed overall when used for its designed purpose

It's great.

Tell us what you particularly liked about the product

Great for fixing and hacking stuff, remouldable, reusable.

Tell us what you particularly disliked about the product

Very hard when set so not ideal for some bike-related tasks, not a glue so surface prep is important.

How does the price compare to that of similar products in the market, including ones recently tested on

There's not much direct competition. It's cheaper than Sugru but not exactly the same thing.

Did you enjoy using the product? Yes

Would you consider buying the product? Yes

Would you recommend the product to a friend? Yes

Use this box to explain your overall score

Really useful stuff to have knocking about, not expensive. Go get some.

Overall rating: 8/10

About the tester

Age: 45  Height: 189cm  Weight: 92kg

I usually ride: whatever I'm testing...  My best bike is: Kinesis Tripster ATR, Merida Scultura

I've been riding for: Over 20 years  I ride: Every day  I would class myself as: Experienced

I regularly do the following types of riding: road racing, time trialling, cyclo-cross, commuting, touring, club rides, sportives, general fitness riding, fixed/singlespeed, mountain biking, Mountain Bike Bog Snorkelling, track

Dave is a founding father of, having previously worked on Cycling Plus and What Mountain Bike magazines back in the day. He also writes about e-bikes for our sister publication ebiketips. He's won three mountain bike bog snorkelling World Championships, and races at the back of the third cats.

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